Recording and identification of cardiac neuron activity in the right atrium ganglionated plexus

Recent multichannel electrode array technology has enabled the simultaneous recording of multiple cardiac neurons located in ganglia on a beating heart. These new bioelectric signals are contaminated by the electrical activity of the atrial muscle just underneath. These atrial waveforms may mask relevant neuronal activity. In this paper, we evaluate the application of a principal component analysis technique to suppress atrial activity (AA) and reveal hidden neuronal activity. Neuronal signals were recorded in situ using a 16-channel electrode in an open-chest, anesthetized dog in sinus rhythm. Validation of AA cancellation was performed by comparing neuron spike waveforms extracted from within AA with those found in AA-free time intervals. Results showed that consistent neuronal waveforms can be identified within AA in order to improve the detection of neuron firings.